Closes #143 - Catch RTDE exceptions in constructor (#148)

* Retry RTDE connection multiple times upon failure
    * Break from loop on successful connection
    * Sleep on failure, to give connection attempt some time to reset

CHANGELOG.md

@@ -30,6 +30,7 @@ This project uses a [CalVer](https://calver.org/) versioning scheme with monthly
 - `coco-to-yolo` conversion now creates a single polygon of all disconnected parts of the mask instead of simply taking the first polygon of the list.
 - Dropped support for python 3.8 and added 3.11 to the testing matrix [#103](https://github.com/airo-ugent/airo-mono/issues/103).
 - Set python version to 3.10 because of an issue with the `ur_rtde` wheels [#121](https://github.com/airo-ugent/airo-mono/issues/121). Updated README.md to reflect this change.
+- `URrtde` will now try connecting to do control interface up to 3 times before raising a `RuntimeError`.
 
 ### Fixed
 - Fixed bug in `get_colored_point_cloud()` that removed some points see issue #25.

airo-robots/airo_robots/manipulators/hardware/ur_rtde.py

@@ -7,6 +7,7 @@
 from airo_robots.manipulators.position_manipulator import ManipulatorSpecs, PositionManipulator
 from airo_spatial_algebra import SE3Container
 from airo_typing import HomogeneousMatrixType, JointConfigurationType
+from loguru import logger
 from rtde_control import RTDEControlInterface
 from rtde_receive import RTDEReceiveInterface
 
@@ -44,14 +45,23 @@ def __init__(
     ) -> None:
         super().__init__(manipulator_specs, gripper)
         self.ip_address = ip_address
-        try:
-            self.rtde_control = RTDEControlInterface(self.ip_address)
-            self.rtde_receive = RTDEReceiveInterface(self.ip_address)
 
-        except RuntimeError:
-            raise RuntimeError(
-                "Could not connect to the robot. Is the robot in remote control? Is the IP correct? Is the network connection ok?"
-            )
+        max_connection_attempts = 3
+        for connection_attempt in range(max_connection_attempts):
+            try:
+                self.rtde_control = RTDEControlInterface(self.ip_address)
+                self.rtde_receive = RTDEReceiveInterface(self.ip_address)
+                break
+            except RuntimeError as e:
+                logger.warning(
+                    f"Failed to connect to RTDE. Retrying... (Attempt {connection_attempt + 1}/{max_connection_attempts}). Error:\n{e}"
+                )
+                if connection_attempt == max_connection_attempts - 1:
+                    raise RuntimeError(
+                        "Could not connect to the robot. Is the robot in remote control? Is the IP correct? Is the network connection ok?"
+                    )
+                else:
+                    time.sleep(1.0)
 
         self.default_linear_acceleration = 1.2  # m/s^2
         self.default_leading_axis_joint_acceleration = 1.2  # rad/s^2